Carbureter for internal-combustion engines



-F. H. ROYCE. CARBURETER FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED FEB. 18. I918- Patented J an. 20, 1920. I

Ryce.

o o 1w 0 O O 5 M 3. a. J 1 m h d a E \\V/ w W e s M w 10 l w W UNITED STATES PATENT OFFICE;

FREDERICK HENRY ROYCE, OI DERBY, ENG-LAND, AS$IGNOR TO ROLLS-ROYCE LIMITED, OF DERBY, ENGLAND.

CARIBURETER FOR INTERNAL-COWLEUSTION ENGINES.

Application filed February 18, 1918.

To all whom it may concern:

Be it known that I, FREDERICK HENRY ROYCE, of Derby, in the county of Derby, England, and a subject of the King of England, have invented certain new and useful Improvements in Carbureters for Internal- Combustion Engines, of which the following is a specification.

This invention relates to carbureters in which the ratio of fuel to air can be, and normally is, automatically controlled by the suction of the engine without any moving mechanism; for example, of the type in use in which the fuel is fed through a vertical tubular nozzle or jet comprising in addi tion to a central pipe affording a supply, two annular narrow chambers arranged around such pipe and concentrically therewith and communicating with one another by openings at difierent levels below the normal or float tank level of the fuel, one of said chambers being open at the top to the induction pipe of the engine and the other in communication with the atmosphere, into which pipe and chambers the fuel flows by gravitation from the float chamber.

Examples of the type referred to are shown in English Letters Patent Nos. 2752 and 10638, A. n. 1912.

In this type of carbureter it is necessary to predetermine the normal passage area of the pipe or passage way from the float chamher to the nozzle or jet which under normal conditions remains constant, but if the engine is to be subjected to varying condi tions, as in the case of an aero engine mounting to high altitudes, it is desirable that the otherwise constant passage should be adjustable.

Several methods have been used in such engines for regulating the flow of liquid fuel to meet such cases by means of an adjustable needle or cone valve or the like, and each has suffered from one or other of the following defects; firstly, engine vibrations have caused the operating gear to move the adjustable valve, and consequently disturb the setting of said valve; secondly, there has been a danger of the valve binding or sticking; thirdly, the adjustment has been too coarse, with the result that the manipulation of the operating handle or lever required great care, and fourthly difiiculties have arisen in initially setting the valve to produce the required effect involving the Specification of Letters Patent.

Patented Jan. 20, 1920.

Serial No. 217,906.

preferably located in an auxiliary circular chamber in communication with the float tank and extendedat bottom and top respectively below and above the base and top cover of the float tank. The bottom of the auxiliary chamber communicates with the pipe or passage leading to the nozzle jets through a cone valve designed to give the desired normal flow when initially set as hereinafter explained, the conical portion of the valve being attached to and operated by a spindle which extends to and passes through the upper end of the chamber, and is guided so that it cannot be decentralized in relation to the valve seat.

The upper part of the valve spindle is threaded and two nuts are provided to screw thereon, one of said nuts forming a seating or flange against which impinges a movable threaded sleeve or nut hereinafter referred to, or such other member as may be used in place thereof, and the other nut serving as a lock-nut.

The valve after being initially set, as hereinafter explained, is preferably adjusted to meet abnormal circumstances by the axial movement of the threaded sleeve acting against the seating constituted by the nut hereinbefore referred to and engaging a screw thread on a fixed sleeve, and a spring acting in opposition thereto.

By the mechanism above described the normal or initial predetermined setting of the cone valve depends upon the position of the said nut forming a seating and this can be determined and secured independently of the adjusting mechanism.

The lock-nut is made of a predetermined thickness corresponding to the desired distance which the conical portion of the valve must be lifted from its seat to secure the required passage area of the valve opening at the normal or initial setting. By this means the original setting of the cone valve can be effected without having to experiment with the engine in the manner hereinafter explained. To the movable threaded sleeve or nut there is clipped or otherwise fastened a lever by which the sleeve or nut can be rotated. Around part of the periphery of the sleeve there are preferably provided one or more marks or graduations in the form of a measured scale and on the lever is an arrow head or pointer pointing thereto. By this means if it is found necessary to make any small adjustment of the setting of the valve, by temporarily loosening the fastening of the lever, the sleeve can be rotated relatively to the lever and by observing the position of the pointer relatively to the mark or marks or scale, the extent to which adjustment had been made can always be known.

In the accompanying drawings is shown an example of the invention.

Figure 1 is a sectional elevation of sufficient of a carbureter for comprehension of the invention,

Fig. 2 is a plan view of the adjusting mechanism and Fig. 3 an elevation of same from the left of Fig. 2.

In said drawings a designates the float chamber of the carburetor, b the auxiliary chamber; 0 a passage connecting said two chambers; (Z a passage between chamber Z) and the nozzle jet (Z 6 is a tubular plug forming the upper closure of the chamber 2) and c an externally threaded tubular extension of said plug. f is a sleeve or nut threaded internally and engaging with said tubular extension; 9 is a plug forming the I base of the auxiliary chamber 6 and constituting the seat of the valve; h is the conical portion of the valve, which has a guide member 7L fitting the plug 9 and is attached to or formed integrally with a spindle or rod b 7&3 is a collar fixed on the spindle 7L and h* a spring abutting at opposite ends against the plug (2 and collar 72,3 respectively to de press the spindle in opposition to the lifting mechanism. 2' is a stop nut having a broad based seating or flange 2' to rest on the upper end of the sleeve f; 7:: is a lock-nut, the thickness of which determines the lift of the conical portion h of the valve from its valve seat 9, Z is a lever attached as by clip Z on the sleeve f; m is a measured scale on the sleeve f; m a knurled surface to enable the sleeve when freed from the lever to be rotated by hand and m is the arrow head or pointer on the lever Z.

With apparatus such as described, the initial setting of the valve is effected by first inserting the conical portion of the valve right home on its seating before applying the nuts 2' and is, then screwing on the nut 2' until it seats on the sleeve f but without lifting the valve from its sea-t, thereupon filing off the external end of the spindle 7L flush with the upper surface of the nut i and finally screwing the spindle further through the nut 71 and through the lock-nut until the end of the spindle is flush with the upper surface of said lock-nut is.

When this is done the valve will be set as predetermined and the lever Z can be fixed on the sleeve f and the valve operated by the lever to make adjustments for abnormal conditions and a predetermined increase or decrease of flow equal for all practical purposes will be secured by every unit of angular movement of the lever within the operable range. The apparatus will thus be free from all the defects previously specified above.

It may be desirable to mark the measured scale m after the valve is set so that its relation to the arrow head m can be definitely shown. Should it be necessary to adjust the normal or initial setting of the valve the clip fastening Z is slackened and the sleeve f rotated by hand, the fastening being then again secured. The extent of the previous adjustment will be always known to facilitate any subsequent adjustment.

Although there has been described as a means of securing the initial setting the provision of two nuts in manner aforesaid the invention is not limited to that precise arrangement. The same result might be at tained by three nuts or two nuts and a washer or even a single nut (if some other locking means were supplied) any one of them being used as the gage.

It will be understood that in all carbureters to which this invention applies the area of the passages, the taper of the valve cone, the pitch of the thread of the sleeve and the thickness of the lock nut can be within limits proportioned to meet the exigencies of design.

What I claim as my invention and desire to secure by Letters Patent of the United States is 1. In a carbureter for internal combustion engines, the combination with a float tank and jet; of a fuel valve; a chamber containing a valve seat and communicating with the tank and jet; a valve spindle disposed within the chamber and protruding beyond the same; a stop mounted on the protruding end of the valve spindle; a nut threaded on said spindle end above said stop and having its under face contacting with the same and its outer face flush with the end face of the spindle; and adjusting means for the valve comprising a member on which the stop normally rests, said nut having a definite, predetermined thickness which enables it to act as a gage to determine the normal or initial distance which the valve shall be set from its seat when the parts of the engine are being reassembled, without experimental running of the engine; substantially as described.

2. In a carbureter for internal combustion engines, the combination with a float tank and jet; of a fuel valve; a chamber containing a valve seat and communicating with the tank and jet; an externally-threaded, fixed member mounted on the top of the chamber;

an internally-threaded, movable sleeve engaging said fixed member and extending above the same a valve spindle disposed within said chamber and protruding through and beyond said sleeve; a stop member threaded upon the protruding end of said spindle and having its under face normally resting upon the top of said sleeve; a lock nut threaded on said spindle end above said stop and having its under face in contact therewith and its outer face flush with the end face of the spindle, said lock nut having a definite, predetermined thickness which enables it to act as a gage to determine the normal or initial distance which the valve shall be set from its seat when the parts of the engine are be ing reassembled, without experimental running of the engine; and means for rotating said sleeve to lift said stop and nut and spindle and thereby adjust the valve independently of its initial setting; substantially as described.

8. In a carburetor for internal combustion engines, the combination with a float tank and jet; of a fuel valve; a chamber containing a valve seat and communicating with the tank and jet; a valve spindle disposed within the chamber and protruding beyond the same; a nut threaded on the protruding end of the spindle and having its outer face flush with the end face of the spindle; supporting means cooperative with the nut for holding the spindle in position, said nut having a definite, predetermined thickness which enables it to act as a gage to determine the normal or initial distance which the valve shall be set from its seat when the parts of the engine are being reassembled, without experimental running of the engine; and means associated with said supporting means for effecting endwise movement of said spin dle independently of its initial setting; substantially as described.

4:. In a carbureter for internal combustion engines, the combination with a float tank and jet; a fuel valve; a chamber containing a valve seat and communicating with the tank and jet; a valve spindle disposed within the chamber and protruding beyond the same; a nut threaded on the protruding end of the spindle and havin its outer face flush with the end face of the spindle; a pair of co-acting supporting members for holding the spindle in position, one member being carried by the spindle and engaging the under face of the nut, and the other member having its upper end engaging the under face of the first member, said nut having a definite, predetermined thickness which enables it to act as a gage to determine the normal or initial distance which the valve shall be set from its seat when the parts of the engine are being reassembled,

, without experimental running of the engine;

and means for adjusting said other member to effect endwise movement of said spindle independently of its initial setting; substantially as described.

5. In a carbureter for internal combustion engines, the combination with a float tank and jet; of a fuel valve located remote from the fuel jet between the latter and the float tank and operable independently of the engine throttle; a chamber containing a valve seat and communicating with said tank and jet; a valve spindle disposed within the chamber and protruding beyond the same; a nut threaded on the protruding end of the spindle and having its outer face flush with the end face of the spindle; supporting means cooperative with the nut for holding the spindle in position, said nut having a definite, predetermined thickness which en ables it to act as a gage to determine the normal or initial distance which the valve shall be set from its seat when the parts of the engine are being reassembled, without experimental running of the engine; and means associated with said supporting means for effecting endwise movement of said spindle independently of its initial setting; sub stantially as described.

6. In a carburetor for internal combustion engines, the combination with a float tank and jet; of a fuel valve located remote from the fuel jet between the latter and the float tank and operable independently of the engine throttle; a chamber containing a valve seat and communicating with said tank and jet; an externally-threaded, fixed member mounted on the top of the chamber; an internally-threaded movable sleeve engaging said fixed member and extending above the same; a valve spindle disposed within said chamber and protruding through and beyond said sleeve; a stop member threaded upon the protruding end of said spindle and having its under face normally resting upon the top of said sleeve; a lock nut threaded on said spindle end above said stop and having its under face in contact therewith and its outer face flush with the end face of the spindle, said lock nut having a definite, predetermined thickness which enables it to act as a gage to determine the normal or initial distance which the valve shall be set from its seat when the parts of the engine are being reassembled, without experimental running of the engine; and a lever detaclr ably connected to said sleeve to rotate the sleeve so as to lift said stop and nut and spindle and thereby adjust the valve independently of its initial setting; substantially as described.

In witness whereof I have signed this specification in the presence of two witnesses.

FREDERICK HENRY ROYCE.

Witnesses:

H. R. CUTTER, 1 Persons. 

